Get rid of FBism in `Config`

Summary: `cwd` was needed for FB-internal reasons, was untyped, and goes away.

Reviewed By: martinbigio

Differential Revision: D4986076

fbshipit-source-id: b093476cabc4f73fb63d37052f4041073c174f06

local-cli/util/Config.js

@@ -119,7 +119,7 @@ const Config = {
     const configPath = findConfigPath(startDir);
     return configPath
       ? this.loadFile(configPath, startDir)
-      : {...defaultConfig, cwd: startDir};
+      : {...defaultConfig};
   },
 
   loadFile(
@@ -131,7 +131,7 @@ const Config = {
       require(pathToConfig) :
       // $FlowFixMe nope
       require(path.join(cwd, pathToConfig));
-    return {...defaultConfig, ...config, cwd};
+    return {...defaultConfig, ...config};
   },
 };